1. Field of the Invention
This invention relates to a digital-to-analog converter and, more specifically, to a digital-to-analog converter which can deal with digital signal whose number of bits exceeds the number of bits which analog-to-digital converter module used as its core can treat.
2. The Prior Art
Although digital signals, instead of analog signals, are mainly processed in the information processing electronics nowadays, analog signals are still used at interfaces between equipments. Therefore, digital-to-analog converters are necessary to convert digital signals in equipments to analog signals to provide them at their interfaces.
Usually a digital-to-analog converter converts digital signal of predefined number of bits to analog signal. The number of bits is specified for each device and it cannot treat the number of bits that exceeds the predefined number.
As the resolution of a digital-to-analog converter equipped in a certain electronics is fixed, it must be replaced to that of higher resolution if higher resolution is required.
But it is not easy to replace a digital-to-analog converter to another one once it has been equipped, and the price of analog-to-converter with high-resolution is expensive. That is, it is difficult for manufacturers and users to improve the resolution of digital-to-analog converter that is already equipped in electronics and, therefore, the versatility and the applicability of the electronics become poor.